Function description:
1. Universal serial bus (Universal Serial Bus, abbreviation: USB) is not only a serial bus standard connecting computer system and external devices, but also a technical specification of input and output interface. It is widely used in personal computers and mobile devices and other related fields, such as photographic equipment, digital television (set-top box), console and other related fields.
2. USB can be connected to devices such as mice, keyboards, game handles, joysticks, scanners, digital cameras, printers, hard drives, and network components. It has only four wires and two power supplies, so after using the USB cable to connect the phone to the computer, you may encounter a situation where you can only transmit data or can only charge, which may be caused by a failure of the USB data wire.
3. With the popularity of a variety of digital devices, especially MP3 and digital cameras, the number of USB devices around us is gradually increasing. However, although these devices use USB interface, the data lines of these devices are not exactly the same. These data lines are the same at one end of the connection to the PC, as shown in the following figure:
However, when connecting to the device side, a variety of interfaces are usually used for volume reasons.
4. B-5Pin: The most common interface, which is gaining popularity among more and more manufacturers because of its superior anti-misinsertion performance and small size, is now widely available on card readers, mp3 players, digital cameras and portable hard drives.
5.B-4Pin: This interface is common in the following brands of digital products: Olympus's C-series and E-series, Kodak's most digital cameras, Samsung's MP3 products (such as Yepp), Sony's DSC series, Compaq's IPAQ series.
Another form of B-4Pin is the B-4Pin flat, which is flatter than the B-4Pin and is widely used in devices.
6.B-8Pin: The interface is similar to a circular connector and is designed to prevent misinsertion of a bump on one side. It can be found in some Nikon digital cameras and is more common in the Coolpix series. While Nikon has always insisted on using this interface, the most popular Mini B 5Pin interface has also been used in some newer models.
7.B-8Pin2*4: It is also a more common interface, such as the famous MP3 series of iRiver, which is called "Iron Triangle" 180TC, as well as many other products in this series. The scope of application of this interface is still wide, but from iRiver since the 3XX series has been completely replaced with the Mini B 5Pin interface, this specification is obviously not as eye-catching as the Mini B 5Pin.
8.Mini USB: Mini USB is divided into A, B and AB. Mini B 5pin is arguably the most common interface, which is gaining traction with many manufacturers because of its excellent anti-misinsertion performance and small size.
9.Micro USB: a portable version of the USB 2.0 standard, smaller than the Mini USB interface used by some mobile phones. Micro-USB is the next generation specification of Mini-USB, developed by the USB Standardization Organization (USB Implementers Forum (USB-IF) on January 4, 2007. Micro-USB supports OTG, like Mini-USB, and is 5pin's. The definition of the Micro series includes the Micro-B series slot used by the standard device; the Micro-AB slot used by the OTG device; the Micro-A and Micro-B plugs, as well as the cable. The unique feature of the Micro series is that they contain stainless steel shells that works well for ten thousand times. At the plenary meeting of the ITU-T Group V (SG5), held in Geneva, Switzerland, on 26 October 2009, the framework standard for "Power adapters and chargers for general mobile terminals and other ICT devices" was discussed and adopted and applied for entry into the approval process. This actually means that mobile phone chargers will be standardized all over the world.
Currently some models of Xiaomi phones, Redmi phones, and Xiaomi tablets use micro USB ports.
10.Micro USB 3.0b public port: commonly used on portable hard disks
11.USB-Type-C: Type-c is a USB interface that can be inserted regardless of sides, and like other other interfaces, it support USB standard charging, data transmission, display output and other functions.
There are also data cables used lightning interface used in apple devices.
Current USB Standards:
| USB版本 | 速率称号 | 频宽 | 速度 |
| USB 3.1 | 超高速 SuperSpeed |
10Gbps | 约1，000MB/s (10，000Mbit/s) |
| USB 3.0 | 超高速 SuperSpeed |
5Gbps | 约500MB/s (5，000Mbit/s) |
| USB 2.0 | 高速 Hi-Speed |
480Mbps | 约60MB/s (60，000KB/s) |
| USB 1.1 | 全速 Full Speed |
12Mbps | Does it help? Yes No |